Impact of Intravenous Lidocaine During Colorectal Surgery on Pain and Immune Functions

Hypothesis: We hypothesize that the intravenous lidocaine (IVL) versus placebo administered during laparoscopic colorectal surgery will allow for: a reduction in intraoperative remifentanil consumption, an improvement in patients' early rehabilitation after surgery, and an enhancement of the immune profile of our patients through an increase in the balance Th1/Th2 and cellular immunity. Background: so far, IVL was shown to have several properties: analgesic, anti-inflammatory, and anti-hyperalgesic. Its effects on rehabilitation and pain are still controversial except for abdominal surgery. To date, no study evaluated the impact of IVL in colorectal surgery on intraoperative consumption of remifentanil. Postoperative immune suppression is multifactorial and depends on the surgical traumatism, but also on the doses of opioids given during anesthesia. No study evaluated in colorectal surgery the impact of IVL on postoperative cellular immunity and on the risk of cancer recurrence. Specific Objectives: primary objective: to reduce by 30% the consumption of remifentanil in the IVL group versus the placebo group; secondary objectives: to evaluate the quality of recovery from anesthesia in the OR (awakening and extubation time), in the PACU and on the wards (pain scores, opioid consumption with patient controlled analgesia (PCA), postoperative nausea and vomiting (PONV), transit recovery time, time in PACU and time in hospital), and to evaluate the postoperative inflammatory parameters and adaptative immune functions (Th1/Th2) until postoperative 48h. Methods: 60 adult patients ASA 1-3 scheduled for elective laparoscopic colorectal surgery will be included in this randomized controlled trial. Randomisation will be into group Control (C) and Lidocaine (IVL). Anesthesia and monitoring will be standardized and accompanied with the monitoring of the depth of anesthesia (BISpectral index, Medtronic) and the depth of analgesia (NoL index, Medasense LTD, recorded on an observational manner). IVL group will blindly be administered intravenous 1.5 mg/kg lidocaine bolus and then 1.5 mg/kg/h until the end of the surgery as previously described. C group will receive the same amount (ml) of placebo. Statistics: a preliminary analysis (idem group C) showed that the total amount of remifentanil given for this type of surgery was 2481+/-985 mcg (duration 141+/-30Min). Considering that we wish to reduce by 30% the remifentanil consumption in the group IVL, the number of patients to be included per group is 30 (alpha 0.05 and beta 20%). Significance/Importance: this study will evaluate the impact of IVL on intraoperative consumption of remifentanil but also on immune functions after surgery in order to reduce the risk of cancer recurrence. If this study brings positive results, this will lead to a significant change in clinical practice of anesthesia. This is a pilot study on the immune functions, but this might bring very strong results to ask for future grants on the impact of IVL on cancer recurrence. Study Design: Prospective, randomized controlled study. Subject Population: Adult patients scheduled to undergo elective laparoscopic colorectal surgery under general anesthesia. Sample Size: 60 patients will be evaluated in this study. Study Duration: 1 year. Study Center: Maisonneuve-Rosemont Hospital, CIUSSS de l'Est de l'Ile de Montreal, Montreal, Quebec, Canada. Adverse Events: None expected.